[3DTV/FTV/multi-view-related topics]
| Title | A Fast Graph Cut Algorithm for Disparity Estimation |
| Author | Cheng-Wei Chou, Jang-Jer Tsai, Hsueh-Ming Hang, Hung-Chih Lin (National Chiao Tung University, Taiwan) |
| Page | pp. 326 - 329 |
| Keyword | FTV, stereo correspondence, disparity estimation, graph cut |
| Abstract | In this paper, we propose a fast graph cut (GC) algorithm for disparity estimation. Two accelerating techniques are suggested: one is the early termination rule, and the other is prioritizing the alpha-beta swap pair search order. Our simulations show that the proposed fast GC algorithm outperforms the original GC scheme by 210% in the average computation time while its disparity estimation quality is almost similar to that of the original GC. |
| Title | Parallel Processing Method for Realtime FTV |
| Author | Kazuma Suzuki (Graduate School of Engineering, Nagoya University, Japan), Norishige Fukushima (Graduate School of Engineering, Nagoya Institute of Technology, Japan), Tomohiro Yendo, Mehrdad Panahpour Tehrani (Graduate School of Engineering, Nagoya University, Japan), Toshiaki Fujii (Graduate School of Engineering, Tokyo Institute of Technology, Japan), Masayuki Tanimoto (Graduate School of Engineering, Nagoya University, Japan) |
| Page | pp. 330 - 333 |
| Keyword | FTV, Free Viewpoint Image Generation, Image Based Rendering, Realtime Processing, Parallel Processing |
| Abstract | In this paper, we propose a parallel processing method to generate free viewpoint image in realtime. It is impossible to arrange the cameras in a high density realistically though it is necessary to capture images of the scene from innumerable cameras to express the free viewpoint image. Therefore, it is necessary to interpolate the image of arbitrary viewpoint from limited captured images. However, this process has the relation of the trade-off between the image quality and the computing time. In proposed method, it aimed to generate the high-quality free viewpoint image in realtime by applying the parallel processing to time-consuming interpolation part. |
| Title | Influence of Wavelet-Based Depth Coding in Multiview Video Systems |
| Author | Ismael Daribo, Hideo Saito (Keio University, Japan) |
| Page | pp. 334 - 337 |
| Keyword | wavelet, depth, coding, 3dtv, mvv |
| Abstract | Multiview video representation based on depth data, such as multiview video-plus-depth (MVD), is emerging 3D video communication services raising in the meantime the problem of coding and transmitting depth video in addition to classical texture video. Depth video is considered as a key side information in novel view synthesis within multiview video systems, such as three-dimensional television (3DTV) or free viewpoint television (FTV), wherein the influence of depth compression on the novel synthesized view is still a contentious issue. In this paper, we propose to discuss and investigate the impact of wavelet-based compression of the depth video on the quality of the view synthesis. Experimental results show that significant gains can be obtained by improving depth edge preservation through shorter wavelet-based filtering on depth edges. |
| Title | An Epipolar Resticted Inter-Mode Selection for Stereoscopic Video Encoding |
| Author | Guolei Yang (Peking University, China), Luhong Liang (Institute of Computing Technology, Chinese Academy of Sciences, China), Wen Gao (Peking University, China) |
| Page | pp. 338 - 341 |
| Keyword | Stereoscopic video, Epipolar restriction, Inter-mode selection |
| Abstract | In this paper, we propose a fast inter-prediction mode selection algorithm for stereoscopic video encoding. Different from methods using disparity estimation, candidate modes are generated by sliding a window along the macro-block line restricted by the epipolar. Then the motion information is utilized to rectify the candidate modes. A selection failure handling algorithm is also proposed to preserve coding quality. The proposed algorithm is evaluated using independent H.264/AVC encoders for left and right views and can be extended to MVC. |
| Title | Temporal Consistency Enhancement on Depth Sequences |
| Author | Deliang Fu, Yin Zhao, Lu Yu (Zhejiang University, China) |
| Page | pp. 342 - 345 |
| Keyword | 3D video, temporal consistency, temporal depth filtering, view synthesis |
| Abstract | Currently, depth sequences generated by automatic depth estimation suffer from the temporal inconsistency problem. Estimated depth values of some objects vary in adjacent frames, whereas the objects actually remain on the same depth planes. These temporal depth errors significantly impair the visual quality of the synthesized virtual view as well as the coding efficiency of the depth sequences. Since depth sequences correspond to texture sequences, some erroneous temporal depth variations can be detected by analyzing temporal variations of the texture sequences. Utilizing this property, we propose a novel solution to enhance the temporal consistency of depth sequences by applying adaptive temporal filtering on them. Experiments demonstrate that the proposed depth filtering algorithm can effectively suppress transient depth errors and generate more stable depth sequences, resulting in notable temporal quality improvement of the synthesized views and higher coding efficiency on the depth sequences. |
| Title | Real-Time Free Viewpoint Television for Embedded Systems |
| Author | Davide Aliprandi, Emiliano Piccinelli (STMicroelectronics, Italy) |
| Page | pp. 346 - 349 |
| Keyword | Viewpoint, Depth, 3DTV |
| Abstract | In this paper we describe an image-based rendering pipeline for interactive real-time Free Viewpoint Television (FTV) on embedded systems. Description of the processing steps and optimizations implemented targeting the hardware acceleration of a commercial programmable Graphics Processing Unit (GPU) is given. As a result, real-time view synthesis at 70 fps in XGA resolution has bee achieved. Restrictions and modifications introduced to support the application on OpenGL ES 2.0 based GPUs for embedded systems have also been discussed. |
| Title | Power-Aware Complexity-Scalable Multiview Video Coding for Mobile Devices |
| Author | Muhammad Shafique (Karlsruhe Institute of Technology, Germany), Bruno Zatt, Sergio Bampi (Federal University of Rio Grande do Sul, Brazil), Jörg Henkel (Karlsruhe Institute of Technology, Germany) |
| Page | pp. 350 - 353 |
| Keyword | MVC, Mobile Devices, Complexity reduction, Power-Aware, Adaptivity |
| Abstract | We propose a novel power-aware scheme for complexity-scalable multiview video coding on mobile devices. Our scheme exploits the asymmetric view quality which is based on the binocular suppression theory. Our scheme employs different quality-complexity classes (QCCs) and adapts at run time depending upon the current battery state. It thereby enables a run-time tradeoff between complexity and video quality. The experimental results show that our scheme is superior to state-of-the-art and it provides an up to 87% complexity reduction while keeping the PSNR close to the exhaustive mode decision. We have demonstrated the power-aware adaptivity between different QCCs using a laptop with battery charging and discharging scenarios. |
| Title | 3D Pose Estimation in High Dimensional Search Spaces with Local Memorization |
| Author | Weilan Luo, Toshihiko Yamasaki, Kiyoharu Aizawa (The University of Tokyo, Japan) |
| Page | pp. 354 - 357 |
| Keyword | tracking, annealing, twist, particle filter |
| Abstract | In this paper, a stochastic approach for extracting the articulated 3D human postures by synchronized multiple cameras is presented in the high-dimensional configuration spaces. Annealed Particle Filtering (APF) seeks for the globally optimal solution of the likelihood. We improve and extend the APF with local memorization to estimate the suited kinematic postures for a volume sequence directly instead of projecting a rough simplified body model to 2D images. Our method guides the particles to the global optimization on the basis of local constraints. A segmentation algorithm is performed on the volumetric models and the process is repeated. We assign the articulated models 42 degrees of freedom. The matching error is about 6% on average while tracking the posture between two neighboring frames. |
| Title | Free-Viewpoint Image Generation Using Different Focal Length Camera Array |
| Author | Kengo Ando (Graduate School of Engineering, Nagoya University, Japan), Norishige Fukushima (Graduate School of Engineering, Nagoya Institute of Technology, Japan), Tomohiro Yendo, Mehrdad Panahpour Tehrani (Graduate School of Engineering, Nagoya University, Japan), Toshiaki Fujii (Graduate School of Engineering, Tokyo Institute of Technology, Japan), Masayuki Tanimoto (Graduate School of Engineering, Nagoya University, Japan) |
| Page | pp. 358 - 361 |
| Keyword | Free-viewpoint image generation, Image Based Rendering |
| Abstract | The availability of multi-view images including Free-Viewpoint TV. Virtual viewpoint images are synthesized by Image-Based Rendering. In this paper, we introduce a depth estimation method for forward virtual viewpoints and view generation method using a zoom camera in our camera setup to improve virtual viewpoints’ image quality. Simulation results confirm reduced error during depth estimation using our proposed method in comparison with conventional stereo matching scheme. We have demonstrated the improvement in image resolution of virtually moved forward camera. |
[Beyond H.264/MPEG-4 AVC and related topics]
| Title | Decoder-Side Hierarchical Motion Estimation for Dense Vector Fields |
| Author | Sven Klomp, Marco Munderloh, Jörn Ostermann (Leibniz Universität Hannover, Germany) |
| Page | pp. 362 - 365 |
| Keyword | video coding, motion compensation, dense vector field, block matching |
| Abstract | Recent research revealed that the data rate can be reduced by performing an additional motion estimation at the decoder. This paper addresses an improved hierarchical motion estimation algorithm to be used in a decoder-side motion estimation system. A special motion vector latching is used to be more robust for very small block sizes and to better adapt to object borders. A dense motion vector field is estimated which reduces the rate by 6.9% in average compared to H.264/AVC. |
| Title | Edge-Based Adaptive Directional Intra Prediction |
| Author | Feng Zou, Oscar C. Au, Wen Yang, Chao Pang, Jingjing Dai, Xing Wen (The Hong Kong University of Science and Technology, Hong Kong), Yu Liu (Hong Kong Applied Science and Technology Research Institute, Hong Kong) |
| Page | pp. 366 - 369 |
| Keyword | H.264/AVC, intra prediction, edge |
| Abstract | H.264/AVC employs intra prediction to reduce spatial redundancy between neighboring blocks. Different directional prediction modes are used to cater diversified video content. Although it achieves quite high coding efficiency, it is desirable to analyze its drawbacks in the existing video coding standard, since it allows us to design better ones. Basically, even after intra prediction, the residue still contains a lot of edge or texture information. Unfortunately, these high frequency components consume a large quantity of bits and the distortion is usually quite high. Based on this drawback, an Edge-based Adaptive Directional Intra Prediction is proposed (EADIP) to reduce the residue energy especially for the edge region. In particular, we establish an edge model in EADIP, which is quite flexible for natural images. Within the model, the edge splits the macroblock into two regions, each being predicted separately. In implementation, we consider the current trend of mode selection and complexity issues. A mode extension is made on INTRA 16x16 in H.264/AVC. Experimental results show that the proposed algorithm outperforms H.264/AVC. And the proposed mode is more likely to be chosen in low bitrate situations. |
| Title | An Improved Low Delay Inter Frame Coding Using Template Matching Averaging |
| Author | Yoshinori Suzuki, Choong Seng Boon (NTT DOCOMO, INC., Japan) |
| Page | pp. 370 - 373 |
| Keyword | Video coding, Prediction methods, Motion compensation |
| Abstract | This paper presents an efficient inter prediction method for video coding. The method applies the idea of template matching averaging to the conventional motion compensated prediction. While one of the candidate is specified by a motion vector, the remaining candidates are obtained by a template matching without using explicit motion vector. The averaging of multiple predictors reduces coding noise residing in each of the predictors. Simulation results show that the proposed scheme improves coding efficiency up to 4.5%. |
| Title | Generating Subject Oriented Codec by Evolutionary Approach |
| Author | Masaaki Matsumura, Seishi Takamura, Hirohisa Jozawa (NTT Cyber Space Laboratories, NTT Corporation, Japan) |
| Page | pp. 374 - 377 |
| Keyword | Evolutive image coding, coding tools combination, subject oriented codec, lossless image coding |
| Abstract | In this paper, we propose an automatic optimization method for deriving the combination that suits for categorized pictures. We prepare some categorised pictures, and optimize the combination for each category. In the case of optimization for lossless image coding, our method achieves a bit-rate reduction of over 2.8% (maximum) compared to the combination that offers the best bit-rate averagely prepared beforehand. |
| Title | Improved Context Modeling for Coding Quantized Transform Coefficients in Video Compression |
| Author | Tung Nguyen, Heiko Schwarz, Heiner Kirchhoffer, Detlev Marpe (Fraunhofer Institute for Telecommunications, Heinrich Hertz Institute, Germany), Thomas Wiegand (Fraunhofer Institute for Telecommunications, Heinrich Hertz Institute/Technical University of Berlin, Germany) |
| Page | pp. 378 - 381 |
| Keyword | context modeling, transform coding |
| Abstract | Recent investigations have shown that the support of ex-tended block sizes for motion-compensated prediction and transform coding can significantly increase the coding effi-ciency for high-resolution video relative to H.264/AVC. In this paper, we present a new context-modeling scheme for the coding of transform coefficient levels that is particularly suitable for transform blocks greater than 8x8. While the basic concept for transform coefficient coding is similar to CABAC, the probability model selection has been optimized for larger block transforms. The proposed context modeling is compared to a straightforward extension of the CABAC context modeling; both schemes have been implemented in a hybrid video codec design that supports block sizes of up to 128x128 samples. In our simulations, we obtained overall bit rate reductions of up to 4%, with an average of 1.7% with the proposed context modeling scheme. |
[Image/video coding and related topics]
| Title | Bitwise Prediction Error Correction for Distributed Video Coding |
| Author | Axel Becker-Lakus, Ka-Ming Leung, Zhonghua Ma (Canon Information Systems Research Australia (CiSRA), Australia) |
| Page | pp. 382 - 385 |
| Keyword | Distributed Video Coding, Wyner-Ziv Coding, Side Information Generation |
| Abstract | Side information plays a key role in the performance of a Distributed Video Coding (DVC) system. However, the generation of side information often relies on complex motion estimation/interpolation operation. The correlation between the source data and the side information, sometimes referred as virtual channel, is also very difficult to model accurately. In this paper, we propose a bitwise prediction error correction method to improve the quality of the side information during Wyner-Ziv decoding. Whenever a bit error is detected in a bit plane, the less significant bits of the corresponding pixel are adjusted to match the initial prediction. The proposed method has been evaluated using a pixel-domain DVC system and delivers a better coding performance with improved decoding quality and reduced bitrate. |
| Title | Improved Texture Compression for S3TC |
| Author | Yifei Jiang, Dandan Huan (Institute of Computing Technology, Chinese Academy of Sciences, China) |
| Page | pp. 386 - 389 |
| Keyword | computer graphics, texture compression, clustering algorithms |
| Abstract | Texture compression is a specialized form of still image compression employed in computer graphics systems to reduce memory bandwidth consumption. Modern texture compression schemes cannot generate satisfactory qualities for both alpha channel and color channel of texture images. We propose a novel texture compression scheme, named ImTC, based on the insight into the essential difference between transparency and color. ImTC defines new data formats and compresses the two channels flexibly. While keeping the same compression ratio as the de facto standard texture compression scheme, ImTC improves compression qualities of both channels. The average PSNR score of alpha channel is improved by about 0.2 dB, and that of color channel can be increased by 6.50 dB over a set of test images, which makes ImTC a better substitute for the standard scheme. |
| Title | Compression of Pre-Computed Per-Pixel Texture Features Using MDS |
| Author | Wai-Man Pang (Spatial Media Group, Computer Arts Lab., University of Aizu, Japan), Hon-Cheng Wong (Faculty of Information Technology, Macau University of Science and Technology, Macau) |
| Page | pp. 390 - 393 |
| Keyword | Compressed texture features, Gabor wavelet transform, Multidimensional scaling, Compression |
| Abstract | There are many successful experiences on employing texture analysis to improve the accuracy and robustness on image segmentation. Usually, a per-pixel based texture analysis is required, this involves intensive computation especially for large images. While, precomputation and storing of the texture features involves large file space which is not cost effective. To adopt to this novel needs, we propose in this paper the use of multidimensional scaling (MDS) technqiue to reduce the size of per-pixel texture features of an image, while preserving the textural discrminiability for segmentation. As per-pixel texture features will create very large dissimilarity matrix, and make the solving of MDS intractable. A sampling-based MDS is therefore introduced to tackle the problem with a divide-and-conquer approach. A compression ratio of 1:24 can be achieved with an average error lower than 7%. Preliminary experiments on segmentation using the compressed data show satisfactory results as good as using the uncompressed features. We foresee that such a method will enable texture features to be stored and transferred more effectively on low processing power devices or embedded system like mobile phones. |
| Title | Temporal Signal Energy Correction and Low-Complexity Encoder Feedback for Lossy Scalable Video Coding |
| Author | Marijn J.H. Loomans, Cornelis J. Koeleman (VDG Security BV, Netherlands), Peter H.N. de With (Eindhoven University of Technology, Netherlands) |
| Page | pp. 394 - 397 |
| Keyword | Scalable Video Coding, Wavelets, Embedded systems |
| Abstract | We address two problems found in embedded Scalable Video Codec implementations: the temporal signal energy distribution and frame-to-frame quality fluctuations. To solve these problems, we move the temporal energy correction to the leaves of the temporal tree, and feed back the decoded first frame of the GOP into the temporal coding chain. The first modification saves on required memory size, bandwidth and computations, while reducing floating/fixed-point conversion errors and the second is achieved without entropy decoding and an unmodified decoder. |
| Title | Improving Colorization-Based Coding by Using Local Correlation between Luminance and Chrominance in Texture Component |
| Author | Yoshitaka Inoue, Takamichi Miyata, Yoshinori Sakai (Tokyo Institute of Technology, Japan) |
| Page | pp. 398 - 401 |
| Keyword | image coding, colorization, total variation, correlation between luminance and chrominance |
| Abstract | Recently, a novel approach to color image compression based on colorization has been presented. Although the conventional method of colorization-based coding outperforms JPEG in terms of subjective quality, the decoded chrominance components lose the local oscillation that the original images had. We focus on the local correlation that exists between luminance and chrominance in separated texture components, and we present a new colorization-based coding method. Experimental results showed that our coding method can improve the coding efficiency. |
| Title | Video Encoding with the Original Picture as the Reference Picture |
| Author | Taiga Muromoto, Naoya Sagara, Kenji Sugiyama (Seikei University, Japan) |
| Page | pp. 402 - 405 |
| Keyword | Inter-picture prediction, Reference picture, Quantization error, Group of picture |
| Abstract | Inter-picture prediction uses a local decoded picture for the reference, in order to avoid a mismatch between encoding and decoding. However, this scheme does not necessarily result in optimal coding efficiency since it requires encoding the processing altogether. Therefore, we study the use of the original picture as the reference. In this case, although the mismatch causes degradation of the picture quality, the bit amount is reduced. Therefore, we propose an adaptive method based on rate distortion optimization. The original picture is used only in the macroblock, if it is lower cost than the local decoded picture is used. Experimental results show a 0.1 to 1.0 dB gain in PSNR in each sequence. |
| Title | A New Hybrid Parallel Intra Coding Method Based on Interpolative Prediction |
| Author | Cui Wang (Tokyo Institute of Technology, Japan), Akira Kubota (Chuo University, Japan), Yoshinori Hatori (Tokyo Institute of Technology, Japan) |
| Page | pp. 406 - 409 |
| Keyword | hybrid parallel coding, interpolative prediction, new shape of block |
| Abstract | The hybrid coding method to combine the predictive coding with the orthogonal transformation and the quantization is mainly used recently. This paper proposes a new hybrid parallel intra coding method based on interpolative prediction which uses correlations between neighboring pixels. For high performance and parallel, the optimal quantizing scheme and the new shape of the block are used. The result of experiments shows that the proposed technique achieves 1~4 dB improvement in Luminance PSNR, especially for image with more details. |
| Title | RBF-Based VBR Controller for Real-Time H.264/SVC Video Coding |
| Author | Sergio Sanz-Rodríguez, Fernando Díaz-de-María (Carlos III University of Madrid, Spain) |
| Page | pp. 410 - 413 |
| Keyword | Rate Control, Variable Bit Rate, Scalable Video Coding, H.264/SVC, streaming |
| Abstract | In this paper we propose a novel VBR controller for real-time H.264/SVC video coding. Since consecutive pictures within the same scene often exhibit similar degrees of complexity, the proposed VBR controller allows for just an incremental variation of QP with respect to that of the previous picture, so preventing unnecessary QP fluctuations. For this purpose, a RBF network has been carefully designed to estimate the QP increment at each dependency (spatial or CGS) layer. A mobile live streaming application scenario was simulated to assess the performance of the proposed VBR controller, which was compared to a recently proposed CBR controller for H.264/SVC. The experimental results show a remarkably consistent quality, notably outperforming the reference CBR controller. |
| Title | Scalable Video Compression Framework with Adaptive Multiresolution Directional Filter Bank Design |
| Author | Lingchen Zhu, Hongkai Xiong (Shanghai Jiao Tong University, China) |
| Page | pp. 414 - 417 |
| Keyword | Scalable video coding, directional filter banks, multiscale geometric, sparse coding |
| Abstract | Regarding orientation resolution as an isolated variable from scale, this paper proposes a dual (scale and orientation) multiresolution transform into scalable video coding (SVC) framework. By projecting 2D signals (textures and edges) onto nonuniformly divided orientation subspaces, the dual multiresolution SVC (DMSVC) can capture 2-D curve smoothness with less coefficients, and provide more flexible spatial decomposition structures than traditional wavelet-based SVC (WSVC). In the spatial decomposition module of DMSVC, the nonuniform directional distribution along scale of each frame is detected by phase congruency in the overcomplete wavelet domain. The corresponding orientational multi-resolution is achieved by nonuniform directional filter banks (NUDFB) which is fulfilled via a non-symmetric binary tree (NSBT) structured frequency division. The wavelet basis function in each scale is converted to an adaptive set of nonuniform directional basis by employing nonuniform directional filter banks. Experimental results validate a superior coding performance and visual quality over WSVC especially on those sequences full of directional edges and textures. |
| Title | A Four-Description MDC for High Loss-Rate Channels |
| Author | Meilin Yang, Mary Comer, Edward J. Delp (School of Electrical and Computer Engineering, Purdue University, U.S.A.) |
| Page | pp. 418 - 421 |
| Keyword | MDC: four-description MDC, high packet loss rate, Gilbert model |
| Abstract | One of the most difficult problems in video transmission is communication over error-prone channels, especially when retransmission is unacceptable. To address this problem, Multiple Description Coding (MDC) has been proposed as an effective solution due to its robust error resilience. Considering applications in scalable, multicast and P2P environments, it is advantageous to use more than two descriptions (which is designated multi-description MDC in this paper). In this paper, we present a new four-description MDC for high loss-rate channel using a hybrid structure of temporal and spatial correlations. A Gilbert model is used as the channel model for burst packet loss simulation. Experimental results demonstrate the efficacy of the proposed method. |
| Title | Bi-Directional Optical Flow for Improving Motion Compensation |
| Author | Alexander Alshin, Elena Alshina, Tammy Lee (Samsung Electronics Co., Ltd., Republic of Korea) |
| Page | pp. 422 - 425 |
| Keyword | bi-directional prediction, optical flow |
| Abstract | New method improving B-slice prediction is proposed. By combining the optical flow concept and high accuracy gradients evaluation we construct the algorithm which allows pixel-wise refinement of motion. This approach does not require any signaling for decoder. According to tests with WQVGA sequences bit-saving of 2%-6% can be achieved using this tool. |
[Image/video processing and related topics]
| Title | Two-Dimensional Chebyshev Polynomials for Image Fusion |
| Author | Zaid Omar, Nikolaos Mitianoudis, Tania Stathaki (Imperial College London, U.K.) |
| Page | pp. 426 - 429 |
| Keyword | Image and data fusion, Chebyshev polynomials, orthogonal moments |
| Abstract | This report documents in detail the research carried out by the author throughout his first year. The paper presents a novel method for fusing images in a domain concerning multiple sensors and modalities. Using Chebyshev polynomials as basis functions, the image is decomposed to perform fusion at feature level. Results show favourable performance compared to previous efforts on image fusion, namely ICA and DT-CWT, in noise affected images. The work presented here aims at providing a novel framework for future studies in image analysis and may introduce innovations in the fields of surveillance, medical imaging and remote sensing. |
| Title | Image Denoising with Hard Color-Shrinkage and Grouplet Transform |
| Author | Takahiro Saito, Ken-ichi Ishikawa, Yasutaka Ueda, Takashi Komatsu (Kanagawa University, Japan) |
| Page | pp. 430 - 433 |
| Keyword | Color-image processing, denoising, wavelet transform, grouplet transform, shrinkage |
| Abstract | To remove signal-dependent noise of a digital color camera, we propose a denoising method with our hard color-shrinkage in the tight-frame grouplet transform domain. The classic hard-shrinkage works well for monochrome-image denoising. To utilize inter-channel color cross-correlations, a noisy image undergoes the color transformation from the RGB to the luminance-and-chrominance color space, and the luminance and the chrominance components are separately denoised; but this approach cannot cope with actual signal-dependent noise. To utilize the noise’s signal-dependencies, we construct the hard color-shrinkage where the inter-channel color cross-correlations are directly utilized in the RGB color space. The hard color-shrinkage alleviates denoising artifacts, and improves picture quality of denoised images. |
| Title | Improved FMO Based H.264 Frame Layer Rate Control for Low Bit Rate Video Transmission |
| Author | Rhandley Domingo Cajote (University of the Philippines, Diliman, Philippines), Supavadee Aramvith (Chulalongkorn University, Thailand) |
| Page | pp. 434 - 437 |
| Keyword | FMO, Rate Control, H.264/AVC, video coding |
| Abstract | The use of Flexible Macroblock Ordering (FMO) in H.264/AVC as an error-resilient tool incurs extra overhead bits that reduces coding efficiency at low bit rate. To improve coding efficiency, we present an improved frame-layer H.264/AVC rate control that takes into consideration the effects of using FMO for video transmission. In this paper, we propose a new header bits model, an enhanced frame complexity measure and a quantization parameter (QP) adjustment scheme. Simulation results show that the proposed method performed better than the existing frame layer rate control with FMO enabled using different number of slice groups. |
| Title | Improvement of Spatial Resolution by Integration of High-Speed Sub-Frame Images |
| Author | Daisuke Kashiwagura, Kanae Matsuzaki, Takayuki Hamamoto (Tokyo University of Science, Japan) |
| Page | pp. 438 - 441 |
| Keyword | super resolution, sub-frame image, high frame rate, motion estimation |
| Abstract | The super resolution technique based on the integration of successive frames depends on the accuracy of the motion estimation. However it requires much amount of calculation and tends to make estimation errors for some images. In this paper, we propose a super resolution method by the motion estimation based on the block matching using high-speed sub-frame images. |
| Title | Improved Autoregressive Image Model Estimation for Directional Image Interpolation |
| Author | Ruiqin Xiong (Peking University, China), Wenpeng Ding (Beijing University of Technology, China), Siwei Ma, Wen Gao (Peking University, China) |
| Page | pp. 442 - 445 |
| Keyword | image interpolation, model estimation, autoregressive model, regularization |
| Abstract | For image interpolation algorithms employing autoregressive models, a mechanism is required to estimate the model parameters piecewisely and accurately so that local structures of image can be exploited efficiently. This paper proposes a new strategy for better estimating the model. Different from conventional schemes which build the model solely upon the covariance matrix of low-resolution image, the proposed strategy utilizes the covariance matrix of high-resolution image itself, with missing pixels properly initialized. To make the estimation robust, we adopt a general solution which exploits the covariance matrices of both scales. Experimental results demonstrate that the proposed strategy improves model estimation and the interpolation performance remarkably. |
[Quality, system, applications, and other topics]
| Title | Subjective Evaluation of Hierarchical B-Frames Using Video-MUSHRA |
| Author | Hussain Mohammed, Nikolaus Färber, Jens Garbas (Fraunhofer IIS, Germany) |
| Page | pp. 446 - 449 |
| Keyword | H.264/AVC, Hierarchical B-Frames, Subjective Quality, MUSHRA |
| Abstract | Hierarchical B-Frames (HBF) has emerged as an efficient video coding tool in recent years. As shown in the literature, this approach results in excellent PSNR gains of >1 dB. However these PSNR gains are not sufficiently assessed in a scientific manner by subjective tests. Hence in this paper, we evaluate HBF coding pattern subjectively by using the MUSHRA test methodology. While MUSHRA is well established in audio coding research, its application to video is a novelty of this paper. We compare HBF with simple IPP coding pattern at either same PSNR or same bit rate. Our results indicate that, HBF gains are clearly subjectively perceptible. Hence, it can be shown that PSNR gains also correlate with a subjective gain. Interestingly, even at same PSNR, HBF is found to be subjectively superior to simple IPP coding. |
| Title | Intra Prediction Architecture for H.264/AVC QFHD Encoder |
| Author | Gang He, Dajiang Zhou, Jinjia Zhou, Satoshi Goto (Waseda University, Japan) |
| Page | pp. 450 - 453 |
| Keyword | H.264, intra prediction, hardware architecture |
| Abstract | This paper proposes a high-performance intra prediction architecture that can support H.264/AVC high profile. The proposed MB/block co-reordering can avoid data dependency and improve pipeline utilization. Therefore, the timing constraint of real-time 4kx2k encoding can be achieved with negligible quality loss. 16x16 prediction engine and 8x8 prediction engine work parallel for prediction and coefficients generating. A reordering interlaced reconstruction is also designed for fully pipelined architecture. It takes only 160 cycles to process one macroblock (MB). Hardware utilization of prediction and reconstruction modules is almost 100%. Furthermore, PE-reusable 8x8 intra predictor and hybrid SAD & SATD mode decision are proposed to save hardware cost. The design is implemented by 90nm CMOS technology with 113.2k gates and can encode 4kx2k video sequences at 60 fps with operation frequency of 310MHz. |
| Title | Compressed Signature for Video Identification |
| Author | Nikola Sprljan, Paul Brasnett, Stavros Paschalakis (Mitsubishi Electric R&D Centre Europe, U.K.) |
| Page | pp. 454 - 457 |
| Keyword | video descriptor, lossless compression |
| Abstract | This paper presents a new application-specific lossless compression scheme developed for video identification descriptors, also known as video fingerprints or signatures. In designing such a descriptor, one usually has to balance the descriptor size against discriminating power and temporal localisation performance. The proposed compression scheme alleviates this problem by efficiently exploiting the temporal redundancies present in the video fingerprint, allowing highly accurate fingerprints which also entail low transmission and storage costs. In this paper we provide a detailed description of our compression scheme and a comparative evaluation against well known state-of-the-art generic compression tools. |
| Title | A Subjective Image Quality Metric for Bit-Inversion-Based Watermarking |
| Author | Tadahiko Kimoto, Fumihiko Kosaka (Toyo University, Japan) |
| Page | pp. 458 - 461 |
| Keyword | image watermark, subjective quality, perceptually adaptive system |
| Abstract | An image watermarking scheme using the previously proposed bit embedding method is developed. Based on the properties of the bit embedding method, the perceptual model of two kinds of objective quality measures is assumed. Then, the measurements of human subjective image quality are analyzed from the viewpoint of the correlation with these two measures. Thereby, the estimating function that can yield an estimate of the subjective quality from two objective measurements is determined. By using the estimating function, the perceptually adaptive watermarking can be achieved. |